Seattle Genetics Inc. said Friday that its cancer drug Adcetris will carry a warning about a deadly type of brain infection that can occur in patients.
The company said Adcetris will carry a “black box” or boxed warning, the most serious type of warning label. The label will say that patients who take Adcetris can develop progressive multifocal leukoencephalopathy (PML), a rare brain infection. Seattle Genetics said two cases of PML have been reported in Adcetris patients, and a third is suspected.
Adcetris was approved in August 2011 for the treatment of Hodgkin Lymphoma (HL), a rare lymphoma known as systemic anaplastic large cell lymphoma. Adcetris is also an antibody-drug conjugate that combines an antibody and drug and enables the antibody to direct the drug to a target on lymphoma cells known as CD30. Since its approval, some 2,000 patients, worldwide, have received treatment with Adcetris. At that time of its approval, one case of PML was described in the label’s Warnings and Precautions section, the FDA said.
The signs and symptoms of PML may develop over several weeks or months and include mood changes; unusual behavior; confusion; thinking problems; loss of memory; changes in vision, speech, or walking; and decreased strength or weakness on one side of the body.
The company has said that the infection is quite rare disease of the central nervous system which either leads to the death of patient, or causes permanent disability. It does not affect the brain immediately but weakens it first, and then targets the immune system.